Opquast Digital Quality Best Practices

Canonical source: examples/OPQUAST_DIGITAL_QUALITY_BEST_PRACTICES.md in mgifford/ACCESSIBILITY.md This skill is derived from that file. When in doubt, the example is authoritative.

Apply the Opquast Digital Quality Checklist (Version 5, 2025-2030) when building or reviewing web projects. The framework contains 245 rules across 14 categories covering content, privacy, e-commerce, forms, accessibility, security, performance, and more.

Rules are published under Creative Commons BY-SA 4.0. Agents may reference and cite rule text; attribute Opquast and respect the ShareAlike licence — derivatives must use the same licence. See opquast.com for the authoritative source.

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Severity Scale (this skill)

Level	Meaning
Critical	Completely blocks access, purchase, or task completion for a user group
Serious	Significantly impairs access or usability; workaround unreasonable to expect
Moderate	Creates friction; workaround available but burdensome
Minor	Best-practice gap; marginal impact

Category-level severity guidance:

• Security failures (HTTPS, headers, passwords): Critical to Serious
• Forms failures (labels, error handling): Critical to Serious
• Navigation failures (keyboard, focus): Critical to Serious
• Images/Media missing alt/captions: Critical
• Privacy policy missing: Serious
• Presentation contrast: Serious; zoom blocked: Serious
• Content, Links, Identification: Moderate to Minor in most cases
• Server/Performance, Newsletter, Internationalisation: Minor in most cases

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When to Use This Skill

• Building a new website or web application
• Reviewing or auditing an existing site for quality
• Implementing accessibility, security, or privacy features
• Creating e-commerce flows, forms, or navigation systems
• Generating HTML/CSS code that must meet quality standards

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Quick Reference by Category (245 rules across 14 categories)

Category	Rules	Key Requirements
Content	1–14	Metadata (description + OG tags), explicit dates, <abbr> for acronyms, data tables for charts, labelled ads, moderation/abuse-report mechanisms
Personal Data / Privacy	15–29	Privacy link in footer, documented data access/modification process, no third-party-only login, generic auth-failure messages, Referrer-Policy, HTTPS for sensitive data, no sensitive data in URLs
E-Commerce	30–68	No pre-checked opt-ins, availability/delivery time/cost before checkout, explicit pricing incl. tax, two+ payment methods, order confirmation email, invoices online
Forms	69–98	<label for="...">, format/case-sensitivity hints, required indicated in text, password strength + show/hide, aria-invalid, aria-describedby, preserve data on error, correct input type/autocomplete, paste not blocked, disabled buttons not aria-hidden
Identification	99–115	Unique page titles (Page | Site), lang attribute, favicon, address/phone in footer, two+ contact methods, response-time/hours stated
Images/Media	116–127	Meaningful alt, empty alt="" for decorative, image-link alt describes destination, transcripts + synchronised captions, no autoplay, pausable media
Internationalisation	128–135	International dialling codes, country in addresses, hreflang/visible language indicator, lang on <html> and inline changes, translated-language link labels
Links	136–152	Descriptive anchor text (no "click here"), tel: protocol, new-tab warning, file type + size for downloads, no broken internal links
Navigation	153–172	Public content without forced login, no nav pop-ups, homepage link, breadcrumbs, consistent nav placement, visible icon labels, skip links, visible :focus-visible, logical tab order, internal search, sitemap
Newsletter	173–179	Confirmed opt-in, unsubscribe link, one-click unsubscribe, archives online, stated frequency
Presentation	180–196	Consistent visual identity, no colour-only info, contrast 4.5:1 normal / 3:1 large text, meaning survives with styles off, 24×24px+ touch targets, no zoom blocking, responsive layout, print styles
Security	197–217	HTTPS everywhere + HSTS, no mixed content, self-service password reset, no plain-text passwords, X-Content-Type-Options, X-Frame-Options/frame-ancestors, CSP, SRI on third-party scripts, no exposed server versions, SPF/DKIM/DMARC
Server/Performance	218–230	robots.txt, sitemap.xml, proper 404 status (not 200), custom error page with nav, gzip/Brotli, cache-control headers, minified CSS/JS
Structure/Code	231–244	Machine-readable dates (<time datetime>), UTF-8, unique IDs, no meta refresh, heading hierarchy h1>h2>h3, tagged (not scanned) PDFs, <caption>/<th scope> on data tables

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Workflow

1. Identify Applicable Categories

Not all 14 categories apply to every project:

• All web projects: Content, Forms, Identification, Images/Media, Links, Navigation, Presentation, Security, Server/Performance, Structure/Code
• Add if applicable: E-Commerce (online sales), Newsletter (email marketing), Internationalisation (multi-language), Personal Data/Privacy (user accounts/data collection)

2. Consult the Full Rule Text

For the complete rule text, code examples, and rule numbers, consult the canonical Opquast guide or the official checklist directly — this skill summarizes the categories and highest-value patterns rather than reproducing all 245 rules verbatim.

3. Apply During Development

When generating or reviewing code, apply rules as implementation requirements:

• HTML generation: Include metadata, semantic structure, accessible forms, proper alt text
• CSS generation: Ensure contrast ratios, focus styles, responsive layout, print styles
• Server configuration: Set security headers, enable compression, configure caching
• Content review: Check date formats, link text, abbreviation expansion

4. Validate

After implementation, verify against applicable rules. Common automated checks:

• HTML validation and heading hierarchy
• Colour contrast ratios (4.5:1 normal text, 3:1 large text)
• Missing alt attributes
• Missing form labels
• Security headers present
• Broken internal links

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Essential Code Patterns

Page Template Minimum

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8" />
  <meta name="viewport" content="width=device-width, initial-scale=1" />
  <meta name="description" content="Page description here." />
  <meta property="og:title" content="Page Title | Site Name" />
  <meta property="og:description" content="Page description for sharing." />
  <title>Page Title | Site Name</title>
  <link rel="icon" type="image/svg+xml" href="/favicon.svg" />
</head>
<body>
  <a href="#main" class="skip-link">Skip to main content</a>
  <nav aria-label="Main navigation"><!-- ... --></nav>
  <main id="main"><!-- ... --></main>
  <footer>
    <a href="/privacy">Privacy Policy</a>
    <a href="/terms">Terms of Use</a>
  </footer>
</body>
</html>

Accessible Form Field

Use native required on native inputs. aria-required is redundant when required is present and should be omitted to avoid accessibility tree noise (rule 98 principle: don't add ARIA states that duplicate native semantics). Use aria-required only on custom widgets (role="combobox" etc.). Also indicate required state in visible text — an asterisk alone is insufficient unless the convention is explained (rule 71).

<label for="email">
  Email address <span aria-hidden="true">*</span> <span class="hint">(required)</span>
  <span class="hint" id="email-hint">Example: user@example.com</span>
</label>
<input id="email" type="email" autocomplete="email"
  required aria-describedby="email-hint" />

Password Field (rules 75–76, 202–205)

<label for="password">Password</label>
<div class="password-wrapper">
  <input id="password" type="password" aria-describedby="password-hint" />
  <button type="button" aria-controls="password" aria-pressed="false">
    Show password
  </button>
</div>

Security Headers (Server Config)

Strict-Transport-Security: max-age=31536000; includeSubDomains; preload
X-Content-Type-Options: nosniff
X-Frame-Options: SAMEORIGIN
Content-Security-Policy: default-src 'self';
Referrer-Policy: strict-origin-when-cross-origin

Do not expose server software versions in response headers (rule 213) — remove or obfuscate Server and X-Powered-By. Apply Subresource Integrity to third-party scripts/stylesheets (rule 214):

<script src="https://cdn.example.com/library.min.js"
  integrity="sha384-<hash>" crossorigin="anonymous"></script>

Focus and Contrast Styles

:focus-visible {
  outline: 3px solid #005fcc;
  outline-offset: 2px;
}
body {
  color: #1a1a1a; /* ~16:1 contrast on white */
  background: #ffffff;
}

Print Styles

@media print {
  nav, header, footer, .sidebar, .no-print { display: none; }
  body { font-size: 12pt; color: #000; }
  a[href]::after { content: " (" attr(href) ")"; }
}

Accessible Data Table (rules 242–243)

<table>
  <caption>Quarterly revenue by region (USD thousands)</caption>
  <thead>
    <tr><th scope="col">Region</th><th scope="col">Q1</th></tr>
  </thead>
  <tbody>
    <tr><th scope="row">North America</th><td>1,200</td></tr>
  </tbody>
</table>

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WCAG Relationship

Opquast complements WCAG 2.2 rather than replacing it. Key mappings:

Opquast Rules	WCAG Criteria
116 (decorative images alt="")	1.1.1 Non-text Content (A)
117-118 (meaningful alt text)	1.1.1 Non-text Content (A)
121-122 (transcripts, captions)	1.2.2, 1.2.3, 1.2.5
124-127 (no autoplay, pausable)	1.4.2, 2.2.2
131-132 (lang attribute)	3.1.1, 3.1.2
164 (skip links)	2.4.1 Bypass Blocks (A)
165 (focus visible)	2.4.7, 2.4.11 Focus Visible/Appearance
166 (keyboard operable)	2.1.1 Keyboard (A)
167 (logical tab order)	2.4.3 Focus Order (A)
181 (not colour alone)	1.4.1 Use of Color (A)
182 (contrast)	1.4.3, 1.4.6, 1.4.11 Contrast
186 (touch targets 24×24px min)	2.5.8 Target Size Minimum (AA, WCAG 2.2)
193 (no zoom block)	1.4.4 Resize Text (AA)
69-70 (labels, instructions)	1.3.1, 3.3.2
79-80 (error identification)	3.3.1, 3.3.3

Use Opquast as a holistic quality baseline and layer WCAG testing for full accessibility compliance.

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Sustainability Connection

Several Opquast categories directly align with SUSTAINABILITY.md and the Web Sustainability Guidelines:

• Server/Performance (rules 226-230): compression, caching, minification — directly reduce data transfer and energy per page view
• Presentation (rule 193): not blocking zoom; (rule 194): responsive layout — reduce need for separate mobile sites
• Structure/Code (rule 239): no meta refresh — avoids unnecessary page reloads

When applying Opquast Server/Performance rules, cross-reference with SUSTAINABILITY.md for additional guidance on carbon-aware delivery and asset optimisation.

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Definition of Done Checklist

Apply to every project; skip categories not in scope:

Content & Identification

• <meta name="description"> and OG tags on every page
• Unique <title> in Page | Site format
• <html lang="..."> present and correct
• <link rel="icon"> present
• Privacy policy linked from footer
• At least two contact methods available

Forms

• Every field has programmatically associated <label>
• Native required used; aria-required omitted on native inputs
• Required state indicated in visible text, not asterisk/colour alone
• aria-invalid="true" set on invalid fields
• Error messages associated via aria-describedby; prior data preserved on error
• Correct input type and autocomplete values
• Paste not blocked; disabled buttons not hidden via aria-hidden

Images & Media

• Decorative images have alt=""
• Informative images have descriptive alt; image links describe the destination
• All video has synchronised captions
• All audio has text transcript
• No autoplay (audio or video); all media pausable

Navigation & Keyboard

• Skip link present and functional
• :focus-visible styles defined; outline: none not used without replacement
• All content keyboard operable; logical tab order
• Breadcrumbs or equivalent location indicator present

Presentation

• Contrast ≥ 4.5:1 for normal text; ≥ 3:1 for large text and UI components
• Information not conveyed by colour alone
• user-scalable=no and maximum-scale not used
• Touch targets ≥ 24×24px (44×44 recommended)
• Print styles hide navigation; reveal link URLs

Security

• HTTPS on all pages; HTTP redirects to HTTPS; no mixed content
• HSTS header present
• X-Content-Type-Options: nosniff present
• X-Frame-Options or CSP frame-ancestors present
• CSP header present
• SRI on all third-party scripts/stylesheets
• Server/framework version headers not exposed

Server/Performance

• robots.txt present; sitemap.xml present
• Proper 404 status for missing pages (not 200)
• Compression enabled (gzip or Brotli)
• Cache-control headers on static assets
• CSS and JS minified

Structure/Code

• <meta charset="UTF-8"> in every <head>
• No duplicate id attributes within a page
• No <meta http-equiv="refresh">
• Heading hierarchy correct (h1 > h2 > h3, no skips)
• Data tables have <caption> and <th scope="...">
• Internal PDFs are tagged (selectable text), not scanned images

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Key WCAG Criteria

See WCAG relationship table above. Opquast covers all of WCAG 2.2 AA and extends well beyond it into security, privacy, e-commerce, and performance.

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References

• Full best practices guide
• Opquast Digital Quality Checklist — CC-BY-SA 4.0; rule text may be cited with attribution
• opquast.com — authoritative source, training, certification
• TRUSTED_SOURCES.yaml — id: opquast, id: opquast-checklist
• SUSTAINABILITY.md — Server/Performance rules align with WSG

Standards horizon: These rules target WCAG 2.2 AA alongside Opquast v5 (2025-2030). WCAG 3.0 is in development. Monitor: https://www.w3.org/TR/wcag-3.0/